Jaw tool and jaw tool group

ABSTRACT

The invention relates to a pressing tool, crimping tool or cutting tool ( 1; 2; 3 ) with a tool jaw ( 5 ) which is supported at a supporting body ( 24 ) by a guidance ( 28 ) having a remaining measuring degree of freedom ( 26 ). The tool jaw ( 5 ) is supported at the supporting body ( 24 ) in the direction of the measuring degree of freedom ( 26 ) by a mechanical parallel arrangement of an elastic supporting element ( 14 ) and a sensor ( 84 ). Here, the stiffness of the elastic supporting element ( 14 ) is dimensioned such that for the maximum of the effective working force of the pressing tool, crimping tool or cutting tool ( 1; 2; 3 ) the sensor ( 84 ) has a maximum deflection of at least 0.1 mm or at least 1°.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to co-pending European patentapplication No. EP 17 168 040.8 filed on Apr. 25, 2017.

FIELD OF THE INVENTION

The invention relates to a jaw tool, i.e. a tool comprising tool jawswhich are used for processing a workpiece wherein the tool jaws aredisplaced or pivoted from an open position to a closed position over aworking stroke. In the following reference will be made to an embodimentof the jaw tool as a pressing tool, a crimping tool or a cutting tool.Furthermore, the invention relates to a jaw tool group comprising jawtools of different types.

A pressing tool might e.g. be embodied as manually actuated pressingpliers for pressing sockets, cubes or fittings as these are e.g.described in one of the publications DE 197 09 639 A1, DE 198 34 859 C2,DE 199 24 086 C2, DE 199 24 087 C2, DE 199 63 097 01, DE 103 46 241 B3(corresponding to U.S. Pat. No. 7,155,954 B2), DE 10 2007 001 235 B4(corresponding to U.S. Pat. No. 8,127,589 B2), DE 10 2008 005 472 B3(corresponding to U.S. Pat. No. 8,245,560 B2), EP 2 995 424 A1(corresponding to U.S. Pat. No. 9,864,948 B2) and EP 2 826 598 A1 or thenot pre-published European patent application EP 16 156 231.9 (publishedas EP 3 208 044 A1, corresponding to US 2017/0239788 A1).

A crimping tool might e.g. be embodied as manually actuated crimpingpliers which serve for crimping a plug or connector to an electricalconductor and/or which might have a design according to the notpre-published European patent application EP 16 156 231.9 or one of thepublications EP 3 012 924 A1 (corresponding to U.S. Pat. No. 9,583,904B2), EP 3 012 923 A1 (corresponding to U.S. Pat. No. 9,634,451 B2), EP 2698 885 A1 (corresponding to US 2014/0047885 A1), EP 2 672 580 A1, EP 2463 969 A2 (corresponding to U.S. Pat. No. 8,601,856 B2), DE 37 08 727C2 (corresponding to U.S. Pat. No. 4,794,780 A), DE 40 23 337 C1(corresponding to U.S. Pat. No. 5,153,984 A), DE 40 26 332 C2, DE 40 39435 C1 (corresponding to U.S. Pat. No. 5,187,968 A), DE 42 41 224 C1, DE44 27 553 C2, DE 197 13 580 C2 (corresponding to U.S. Pat. No. 5,913,933A), DE 197 53 436 C2, DE 198 02 287 C1 (corresponding to U.S. Pat. No.6,053,025 A), DE 198 07 737 C2 (corresponding to U.S. Pat. No. 6,026,671A), DE 298 03 336 U1, DE 198 32 884 01 (corresponding to U.S. Pat. No.6,155,095 A), DE 100 56 900 C1 (corresponding to U.S. Pat. No. 6,612,147B2), DE 101 32 413 C2 (corresponding to U.S. Pat. No. 6,877,228 B2), DE101 40 270 B4, DE 102 42 345 B3 (corresponding to U.S. Pat. No.6,910,363 B2), DE 10 2005 003 615 B3, DE 10 2005 003 617 B3, DE 10 2007038 626 B3 (corresponding to U.S. Pat. No. 8,296,956 B2), DE 10 2008 003524 B4 (corresponding to U.S. Pat. No. 8,113,031 B2), DE 10 2008 012 011B3 (corresponding to U.S. Pat. No. 8,230,715 B2), DE 20 2008 003 703 U1,EP 1 724 101 A1, EP 2 305 428 A1 (corresponding to U.S. Pat. No.8,516,872 B2), DE 10 2010 061 148 A1 (corresponding to U.S. Pat. No.8,601,856 B2), DE 10 2011 052 967 B4 or corresponding to the manualcrimping tool distributed by the applicant prior to the application dateof the present patent application under the labels CS10, CSV10,CSV10-LWL, CSV10-FFC, AE, CS8, CK100, CS30, CS KTVR, CE/CG, CS150,CS200, CS210, CP600.

A cutting tool might e.g. be embodied as manually actuated cable cuttingpliers and/or according to one of the not-pre-published European patentapplications EP 15 191 264.9 (published as EP 3 159 088 A1,corresponding to US 2017/0113367 A1) and EP 15 191 261.5 (published asEP 3 159 107 A1, corresponding to US 2017/0113358 A1) or correspondingto the publication DE 43 03 180 C1 (corresponding to U.S. Pat. No.5,526,570 A) or corresponding to a cutting tool which is distributed bythe applicant at the application date of the present patent applicationunder the label cable cutter SH.

Here, the invention is usable both for manually actuated tools as wellas for tools wherein the actuation is provided under the assistance by anon-manual power source or solely by a non-manual power source (inparticular under the assistance by a pneumatic drive, a hydraulic driveor an electric drive with the option that the electric drive might bepowered via a cable by an external electric power source or also by anaccumulator forming a component of the tool).

BACKGROUND OF THE INVENTION

The publication DE 10 2007 050 176 A1 discloses that when crimping aplug to an electric conductor by crimping pliers, the increasingcomplexity of cable looms, aggravated product liability and extendedwarranty claims require a quality control by a monitoring of thecrimping force. A force measuring device is proposed which might beformed by a piezo-electric force sensor or by strain gauges. The forcemeasuring device is arranged at the exterior of a crimping punch or alsowithin the crimping punch or a crimping accommodation. Furthermore, thecrimping pliers comprise a transmitter which is arranged above thecrimping punch at the crimping pliers head. The transmitter transmits awireless crimping force signal which is received and analyzed by areceiving and analyzing device. The transmitter can be activated anddeactivated by manipulation elements. Furthermore, in some cases it ispossible to adjust the frequency of the transmitter by thesemanipulation elements. In the transmitter a power source embodied as anelectric battery or a rechargeable accumulator is provided for thesupply of power to the transmitter and to the force measuring device. Itis also proposed that the transmitter comprises an induction coilwherein an external magnetic field is able to generate an inductioncurrent used for recharging the accumulator. It is also proposed that asolar cell is mounted to the crimping pliers for recharging theaccumulator. Finally, it is also proposed to provide a temporary cableconnection. The transmitter comprises a display device at which it ispossible to display the crimping force, the transmitting frequency, thepresence of a wireless connection, the loading state of the power sourceand the like. The display device can be embodied as LED or LDC displaydevice. Additionally, a displacement measuring system can be provided atthe crimping pliers for sensing the working stroke of the crimpingpliers. In order to avoid damages, the crimping pliers might comprise alatching device or slipping device which limits the applicable crimpingforce to a predefined force value. It is also proposed thatreceiving-analyzing-device is a commercially available personal computerhaving a Bluetooth receiver.

The publication DE 298 06 179 U1 describes that it is known from DE 4014 221 A1 to monitor the quality of the produced crimping connection ina crimping press by sensing the crimping force. For this purpose, thecrimping punch, the crimping die or the platform is embodied as a springbody with a strain gauge arranges thereat. The displacement of thecrimping punch is sensed by an inductive displacement sensor. On thisbackground, the publication proposes that a crimping force and thecrimping displacement are also sensed for crimping pliers. For thispurpose, a first force sensor is used which directly senses the crimpingforce in the bit of tongs. A second force sensor senses the openingdisplacement of the opening of the bit of tongs so that by means of thissecond force sensor indirectly the crimping displacement is sensed. Asforce sensors here strain gauges or piezo-electric forces sensors areused. A strain gauge can be arranged on a leaf spring which is tensionedduring the closing movement of the crimping pliers. It is also proposedthat the first force sensor is arranged at an intermediate part in thelever drive of the crimping pliers. For a temperature compensation areference sensor can be used. Analyzing circuitry can be provided at thecrimping pliers, the analyzing circuitry comprising a suitable displayfor informing the user of the crimping pliers during the crimpingprocess about the quality of the crimping process. Also a data storagecan be provided at the crimping pliers. In the data storage, it ispossible to store force-displacement-progressions for different types ofcrimps (in particular different types of contacts) so that for aspecific crimp the associated force-displacement-progression isavailable for the monitoring of the quality. A LED display or a liquidcrystal display can be used as an optical display device at the crimpingpliers. Additionally, a signal output via an acoustic indicating deviceis possible. If an acoustic indicating device or an optic display deviceconsisting of LEDs is used, by these devices the successful execution ofa crimping process can be confirmed by different colors or sounds. As aninterface for a stationary computer, a wire-based or tethered interfaceor optical interface or any interface with a transmission over air whichuses electromagnetic radiation in the visible range, infrared range orRF-range for the exchange of data can be used. Here, also abi-directional interface can be used. It is also possible that theclosing movement of the bit of tongs of the crimping pliers is supportedby an electric servomotor. The monitoring of the crimping forceprogression might consist of comparing the measured crimping forceprogression with a predetermined crimping force progression, in somecases with a given tolerance region.

The patent DE 10 2004 009 489 B4 lists publications U.S. Pat. No.5,195,042, DE 298 06 179, DE 199 32 952 (corresponding to U.S. Pat. No.6,072,638 A) and DE 697 00 589 as relevant prior art concerning the useof displacement-force-measuring systems in the technical field ofcrimping. The patent DE 10 2004 009 489 B4 relates to an electronicmonitoring of an adjusting process of crimping pliers.

In the patent application DE 10 2008 030 773 A1 the publications DE 4014 221 A1, DE 43 37 796 A1, DE 199 32 962 A1, DE 298 06 179 U1 and U.S.Pat. No. 5,490,406 A are listed as relevant prior art concerning knownelectronic devices for the force-displacement-measurement in crimpingpliers. Also this patent application relates to the electronicmonitoring of an adjusting process of the crimping pliers. Here, asensor system is used which senses the crimping displacement in anabsolute or incremental fashion. By a control, monitoring and analyzingunit it is possible to generate an electronic indication at an LDCdisplay. A cassette can be used into which a computer system as well asa constructional unit serving as the accommodating device and as theadjusting device with the sensor system are integrated. Constructionalunits can be assembled with and disassembled from already completelyassembled pliers so that an exchange according to the specific needs ispossible.

The European patent EP 1 990 874 B1 (corresponding to U.S. Pat. No.8,079,242 B2) relates to crimping pliers with preferably four punchesbeing pressed radially towards a longitudinal axis of a plug. Here, thepunches are actuated corresponding to a rotational movement of anactuation ring. The actuation movement of the actuation ring is sensedby a sensor. Furthermore, an identification sensor senses identificationdata of a tool for positioning the plug. Here, the identification sensormight be a HF-label. Additionally, another sensor for sensing a movementof a punch and a force sensor for sensing the crimping force can beprovided. The crimping pliers might comprise an interface by which via abi-directional connection data can be transferred. However the transfercan also be provided in a wireless fashion.

The European patent EP 2 043 818 B1 (corresponding to U.S. Pat. No.7,793,571 B2) relates to the provision of a signaling device at manuallyoperated pliers. The signaling device makes the approaching of apredefined closing force tangibly for the hand of the user. Here, thesignaling device is embodied as a vibrator integrated into a hand lever.

The publication EP 2 698 885 A1 (corresponding to US 2014/0047885 A1)discloses a crimping machine wherein different exchangeable adapters areused. The exchangeable adapters each comprise a crimping punch as wellas an anvil. Furthermore, in each of the exchangeable adapters a sensoris integrated by which it is possible to sense a crimping force and/or acrimping displacement. Here, in the different exchangeable adapterssensors having differing measurement regions can be used for differentapplications. A force sensor can be integrated into a recess of theanvil or of the punch of the exchangeable adapter. A deflection of theanvil or the punch should then lead to a bias of the sensor with aforce, the sensor being is arranged within the recess. In this case, theelastically deformable regions of the anvil or the punch are describedto be arranged in mechanical parallel connection to the support via thesensor. The exchangeable adapter and the force sensor of theexchangeable adapter can be calibrated within the factory or after thedelivery of the exchangeable adapter. Determined calibration factors orcalibration curves can be modelled or stored in a control unit which isintegrated into the exchangeable adapter.

Further prior art is known from the publications EP 1 071 173 A2, EP 3067 679 A1, WO 90/00098 A1 and DE 199 32 961 A1.

SUMMARY OF THE INVENTION

The invention bases on the object to propose a jaw tool (in particular apressing tool, crimping tool or cutting tool) as well as a jaw toolgroup comprising jaw tools comprising an integrated sensor and beingimproved with respect to

-   -   the used measurement principle,    -   the manufacturing costs,    -   the biasing of the sensor with the force,    -   a protection of the sensor against an overload,    -   the use for a tool group or for pressing tools, crimping tools        or cutting tools of different types or for different        applications,    -   the calibration of the sensor,    -   the measurement precision and/or    -   the influence of error sources.

One embodiment of the present invention bases on the finding that theperson with skill in the art when equipping a pressing tool, crimpingtool or cutting tool with a force sensor for sensing the working forceassumed that the force sensor has to be integrated in such a way intothe force flow of the pressing tool, crimping tool or cutting tool thatthe stiffness of the components arranged in the force flow is as high aspossible. Also from this reason in pressing tools, crimping tools andcutting tools strain gauges or piezo-electric force sensors are usedwhich feature a high stiffness and the deflections of which aregenerally in the region of a per mill of the extension of the forcesensor in measuring direction.

On the other hand, one embodiment of invention bases on the finding thatforce sensors used at present and their integration into the pressingtool, crimping tool and cutting tool lead to disadvantages. Onedisadvantage is that error sources as in particular vibrations, changesof the temperature and coinciding changes of the dimensions of thecomponents of the pressing tool, crimping tool and cutting tool,manufacturing tolerances as e.g. a play in joints of the drivemechanism, tensions of the material, electric interferences might haveeffects in the order of the deflections which form the basis fordetermining the measurement signal of the force sensor. Accordingly, theforce sensors used according to the prior art in some cases generate ameasurement signal which is imprecise and depends on the aforementionederror sources. A reduction of the influence of error sources of thistype in some cases requires regular post-calibrations.

Embodiments of the invention consider the aforementioned findings byarranging two components in the force flow in the pressing tool,crimping tool or cutting tool. Between the two components, an elasticsupporting element and a sensor are arranged in mechanical parallelarrangement. Due to the mechanical parallel arrangement, the sensor andthe elastic supporting element have deflections which correlate to eachother and which result from an effective working force of the pressingtool, crimping tool or cutting tool over the working stroke. If thecomponents are e.g. moved along a straight line over the working strokerelative to each other, the deflections of the elastic supportingelement and the sensor are the same. If instead the two components arepivoted relative to each other over the working stroke, the relation ofthe deflections of the elastic supporting element and the sensorcorresponds to the relation of the distances of the supporting elementand the sensor from the pivot axis of the components.

By the constructive choice of the stiffness of the elastic supportingelement it is possible to define the extent of the deflection of thesensor during the working stroke of the pressing tool, crimping tool orcutting tool by constructive measures. Here, embodiments of theinvention overcome the above mentioned prejudice of the experts that thedeflection of the sensor has to be as small as possible. Instead,embodiments of the invention propose to dimension the stiffness of theelastic supporting element such that for the maximum of the applicableworking force of the pressing tool, crimping tool or cutting tool thesensor has a maximum of the deflection which is (in the case that thetwo components of the sensor being moved relative to each other aremoved with a translatory relative movement which generates measurementsignal) at least 0.1 mm (in particular even at least 0.2 mm, 0.3 mm, 0.4mm or 0.5 mm, whereas the maximum of the deflection might e.g. be in therange of 0.1 mm to 20.0 mm or 0.1 mm to 15.0 mm or 0.2 mm to 1.0 mm). Ifinstead a sensor is used wherein the components of the sensor beingmoved relatively to each other are pivoted relative to each other andwherein the relative pivoting movement generates the measurement signal,the maximum deflection is at least 1° (in particular even at least 1.5°or 2.0° or 2.5° or 3° or 4.0° or 5.0°, wherein it is possible that themaximum deflection is then e.g. in the region of 1° to 10° or 1.5° to6°). Thus, the maximum deflection of the sensor is in particular atleast one magnitude larger than the deflection which is present forforce sensors according to the prior art, in particular a strain gaugeor a piezo-electric force sensor. Here, the maximum of the effectiveworking force results from the workpieces which have to be worked by thepressing tool, crimping tool or cutting tool. It is also possible thatthe maximum of the working force is calculated from the maximum of thedrive force that can be generated by the drive of the pressing tool,crimping tool or cutting tool (in the case of a drive via hand leversthe maximum of the hand force) and from the transmission ratio of thedrive mechanism used in the pressing tool, crimping tool or cuttingtool. For the example of pressing pliers, crimping pliers or cuttingpliers, DIN defines that the maximum of the hand force for a single handoperation of a pressing tool, crimping tool or cutting tool is a handforce of 250 N so that it is possible to determine the maximum workingforce from a hand force of 250 N which results from the maximum of thehand force of 250 N being effective at the hand levers and a(down-gearing or up-gearing) kinematic of pressing pliers, crimpingpliers or cutting pliers. Accordingly, the elastic supporting element isdimensioned such that for the aforementioned maximum of the hand forcethe deflection of the sensor given above results.

By the inventive use of a comparatively large maximum deflection of thesensor, it is possible to (in some cases significantly) reduce theinfluence of the aforementioned error sources on the measurement signalof the sensor. Accordingly, for the first time an improved measurementof the working force of the pressing tool, crimping tool or cutting toolis provided.

The components between which the elastic supporting element and thesensor are arranged might be any components in the drive mechanism ofthe pressing tool, crimping tool or cutting tool. For a particularproposal of the invention, one component is a tool jaw, whereas theother component is a supporting body. For this design, the supportingelement and the sensor are arranged directly adjacent a pressing die orcrimping die or cutting element. In this way, in some cases themeasurement precision can be further increased. On the other hand, insome cases the integration of the supporting element and of the sensorinto the surrounding region of the tool jaw is particularly simple andspace-saving.

It is possible that within the frame of the invention a tool jaw of thepressing tool, crimping tool or cutting tool is guided for a translatorymovement, for a pivoting or any curved path relative to the other tooljaw. The tool jaw can directly form a cutting edge of the cutting toolor a pressing die or crimping die of the pressing tool or crimping tool.However, it is also possible that a cutting edge or a pressing die orcrimping die is fixed or mounted to the tool jaw or held exchangeablythereat. Preferably, the tool jaw is coupled to the pressing die orcrimping die by a transverse support extending through the crimping dieor pressing die. The transverse support is held in a recess of the tooljaw having an open edge of the cross section as being subject of thepatent DE 198 02 287 C1 (corresponding to U.S. Pat. No. 6,053,025 A).

For another embodiment of the invention, the tool jaw is supported by aguidance at a supporting body. Here, the guidance provides a remainingmeasuring degree of freedom, in particular a translatory measuringdegree of freedom or any curve-shaped measuring degree of freedom. Here,the guidance might have any constructional design, e.g. in the case of atranslatory measuring degree of freedom in the design of a slidingguidance.

For one proposal of the invention, the guidance is a linear guidance. Inthis case, the remaining measuring degree of freedom is a translatorymeasuring degree of freedom of the tool jaw relative to the supportingbody. To mention only one non-limiting example, it is possible that aninventive design is used for a tool having a drive mechanismcorresponding to the drive mechanism of a tool CS 10 or CS 30 of theapplicant.

According to another proposal, the guidance is a pivot joint. In thiscase, the remaining measuring degree of freedom is a pivoting measuringdegree of freedom of the tool jaw relative to the supporting body. Aprovision of the guidance of this type via a pivot joint is possiblewith a simple constructive design with common embodiments of a pivotjoint, in particular with the bearing by a pivot bearing lug and a pivotpin extending through the pivot bearing lug. It is also possible that apivot bearing is extremely robust.

Here, it is possible that the elastic supporting element and the sensorare arranged with different lever arms or distances from a pivot axis ofthe pivot joint. By the constructive choice of the length of thedifferent lever arms, it is possible that in the case of the use of thesensor the size of the deflection of the sensor can be influenced byconstructive measures. On the other hand, due to the different leverarms or distances it is possible to arrange the supporting element andthe sensor with an offset between the tool jaw and the supporting bodyso that in some cases a particularly compact design results. Here, it ispossible that the sensor has a larger lever arm or distance than thesupporting element (or vice versa). Preferably, the difference of thetwo lever arms or distances is larger than the sum of the maximum of thehalf extensions of the supporting element and the sensor in thedirection of the lever arms, in the direction of the distances or in thedirection of the main extension of the tool jaw so that it is possiblethat there is an intermediate space between the supporting element andthe sensor.

It is possible that the pivot joint which forms the guidance solelyserves for guiding the tool jaw relative to the supporting body.However, for another proposal of the invention it is also possible thatthe pivot joint (in particular a pivot pin of the same) ismultifunctional. In this case, the pivot joint (in particular the pivotpin) also forms a pivot joint for another component as e.g. the othertool jaw, the other component being pivotable relative to the tool jawwhich is supported by the supporting element. In this way, a compactdesign results with a reduced number of components.

It is possible that the tool jaw is mounted to or fixed at the sensorand/or the supporting element. For a particular embodiment of theinvention, the tool jaw loosely contacts the sensor and/or thesupporting element. This is e.g. of advantage with respect to thetolerances for the manufacturing of the components of the tool and/orfor the place where the sensor and/or the supporting element is/arearranged. In some cases also a replacement of the sensor and/or thesupporting element or the use of different supporting elements issimplified.

For the loose contact of the tool jaw with the sensor and/or thesupporting element the connection between the tool jaw and the sensorand/or the supporting element is established and/or strengthened overthe working stroke with the increasing working force by the increasingcontact force between the tool jaw and the sensor and/or supportingelement corresponding to the increasing working force.

Furthermore, an embodiment of the invention proposes that the tool jaw,the sensor and/or the supporting element is/are biased by a (in somecases pre-tensioned) spring along the measuring degree of freedom. Here,the spring is in particular effective in opening direction of the tooljaw. In the case that the tool jaw loosely contacts the sensor and/orthe supporting element, the spring presses the tool jaw against thesensor and/or the supporting element such that a certain pre-tension ofthe supporting element and/or the bias of the sensor with a base levelof a sensor force is provided also when no working force is effective.In some cases, the spring force of the spring is split on the one handinto a spring-supporting force biasing the supporting element and aspring-sensor force biasing the sensor. It is also possible that by thespring a tottering of the tool jaw is reduced or avoided if the tool jawloosely contacts the sensor and/or the supporting element.

For the design of the elastic supporting element there are a lot ofoptions. Here, the elastic supporting element might comprise one singlespring element or also a plurality of spring elements being effective inmechanical series arrangement or mechanical parallel arrangement. Here,it is possible that the elastic supporting element is specificallyformed or designed with a linear or non-linear spring stiffness alongthe measuring degree of freedom which might also be adapted to thecharacteristic of the effective guidance and/or a characteristic of thesensor.

For a particular proposal of the invention, the elastic supportingelement comprises an elastomeric body. By the choice of the geometry ofthe elastomeric body (in particular the effective cross sectiontransverse to the measuring degree of freedom and the effective lengthalong the measuring degree of freedom) and by the choice of the materialof the elastomeric body it is possible to define the stiffness of theelastic supporting element by constructive measures.

For one proposal of the invention, the elastic supporting elementcomprises a metallic spring body. In order to mention only somenon-limiting examples, the metallic spring body might be formed by aleaf spring or bending beam or a spiral spring being biased bycompression or pulling.

Another inventive pressing tool, crimping tool or cutting tool comprisesa tool head which is immobile over the working stroke. For the design ofthe tool in a plate construction the tool head might e.g. comprise coverplates. In this case, it is possible that the two tool jaws are guidedby a guidance (in particular a common pivot pin or by a linear guide) atthe tool head. In this case, the guidance also provides a support of thetool jaw at the supporting body with the remaining measuring degree offreedom. In this case, the force flow of the working force runs from thepivoting jaw over the supporting element and in some cases the sensor tothe tool head. Here, the tool head might directly form the supportingbody or the supporting body is (or a plurality of separate supportingbody parts are) directly or indirectly supported or fixed at the toolhead, in particular the cover plates.

Another embodiment of the pressing tool, crimping tool or cutting toolrelates to the design of the tool head with at least one cover platewhich carries the pivot pin and at which the supporting element is(directly or indirectly via the supporting body) supported. It is alsopossible that the sensor is supported or held at the cover plate.

A particularly compact design might result if at least one cover platecomprises a recess into which or through which the supporting elementand/or the sensor extend/extends. This embodiment is in particular ofimportance if the extension of the tool head (in particular the outerdistance of the two cover plates) in a direction transverse to the pivotplane of the tool jaws is chosen to be smaller than theextensions/extension of the supporting element and/or the sensor in thisdirection. In this case, it is generally possible to keep the extensionof the tool head in this direction small, whereas the supporting elementand/or the sensor are/is “nested” with the tool head or the cover plateor at least partially extend/extends through the tool head or the coverplate.

For the design of the sensor the invention in particular proposes twopossible variants:

a) It is possible that the sensor is a displacement sensor. Due to thefact that the tool jaw is supported via the supporting elements at thesupporting body, dependent on the bias of the tool jaw and so of thesupporting element with a crimping force, a pressing force or a cuttingforce (here also together “working force”) a displacement of the tooljaw along the measuring degree of freedom results. This displacement canbe sensed by the displacement sensor with a resulting measurementsignal. Then, it is possible the convert the measurement signal into theeffective working force. The conversion factor here depends on thestiffness of the supporting element (and in the case of a pivotingbearing of the two tool jaws from the distances of the displacementsensor and the elastic supporting element from the pivot axis).

b) Alternatively, it is possible that the sensor is a force sensor. By amechanical parallel arrangement of the supporting element and the forcesensor, a working force biasing the tool jaw can be split on the onehand into a supporting force which biases the elastic supporting elementand on the other hand into a sensor force biasing the force sensor.Dependent on the arrangement, geometry and stiffness of the elasticsupporting element, in this way it is possible to define the absolutevalue of the maximum of the sensor force biasing the force sensor byconstructive measures. So, it is e.g. possible to keep the sensor forcecomparatively small over the working stroke when using a comparativelylarge stiffness of the elastic supporting element. In this way accordingto an embodiment of the invention it is for the first time possible touse a force sensor of a type for which the person with skill in the artfor the here applicable tool without knowledge of the invention assumedthat a force sensor of this type would be damaged by a use in a crimpingtool, pressing tool or cutting tool due to the high effective workingforces. If the same or different tools are used for different diesand/or applications with different maximums of the working forces, by anexchange or by an adaptation of the elastic supporting element and achange of the splitting of the working force into the sensor force andinto the supporting force resulting therefrom it is neverthelesspossible to use the same force sensors. In order to mention only somenon-limiting examples, the supporting force being accommodated by thesupporting element might be at least by the factor 10, 20, 50 100 oreven 300 larger than the sensor force accommodated by the force sensor.

In the case that it is of interest to avoid that the force sensor isbiased by excess sensor forces which might lead to a damaging of theforce sensor, an embodiment of the invention proposes that the pressingtool, crimping tool or cutting tool comprises a limiting device. By thelimiting device the sensor force biasing the force sensor is limited.For the design of the limiting device there are a lot of options. It ise.g. possible that for a certain movement of the tool jaw along themeasuring degree of freedom with the coinciding elastic bias of theelastic supporting element the tool jaw abuts a stop (e.g. a stop of thesupporting body or the tool head). Due to the contact with the stop, afurther increase of the working force leads to the result that anotherforce component of the working force is supported by the stop. In thecase of a rigid stop, the stop limits the sensor force to the sensorforce being effective at the point in time when the tool jaw initiallycontacts the stop. If instead the stop is elastic, the elasticallysupported stop provides an additional supporting spring which isarranged in parallel arrangement to the elastic support by thesupporting element. Another possible option for a design of a limitingdevice might be the use of a slipping clutch. The slipping clutch mighte.g. be effective in the force flow between the force sensor and/or thesupporting element and the tool jaw and/or the supporting body such thatwith a slipping of the slipping clutch when exceeding a predeterminedthreshold value of the working force the force sensor is not furtherbiased with a sensor force. However, it is also possible that theslipping clutch is integrated into the drive mechanism of the pressingtool, crimping tool or cutting tool such that the actuation forces ofthe pressing tool, crimping tool or cutting tool are limited andindirectly also the sensor force is limited. One example of a limitingdevice of this type is e.g. described in the publication EP 2 826 598B1. A very simple limiting device can be provided if the elasticsupporting element has a design and is dimensioned such that whenreaching the maximum of the supporting force the elastic supportingelement establishes a full contact or blocking contact such that afurther deformation is not possible and a further increase of theworking force does not lead to an increase of the sensor force but onlyto an increase of the supporting force.

Within the frame of the invention, it is generally possible to use anyforce sensor. For one particular proposal of the invention, the forcesensor comprises an elastic sensor body. To mention only somenon-limiting examples, the elastic sensor body might be an elastomericbody formed as a hemisphere or calotte, as a half cylinder or with anyother shape. The sensor body forms a contact surface or a contact areawith a sensor surface of the force sensor. If the sensor force biasesthe elastic sensor body, this leads to an elastic deformation of thesensor body coinciding with a change of the size of the contact areabetween the elastic sensor body and the sensor surface. Here, the sizeof the contact area depends on the sensor force biasing the force sensorwith a given dependency. Then, the force sensor determines the size ofthe contact area and converts the determined size of the contact area(in particular by the aforementioned given dependency, a characteristicmap, a calibration curve or any a-priori given conversion function) intoa force measurement signal.

For the type of the determination of the size of the contact area in theforce sensor, any measurement principle might be used. It is e.g.possible that a transition resistance between the elastic sensor bodyand the contact surface which depends on the size of the contact area isevaluated. It is also possible that the sensor surface of the forcesensor comprises a series or matrix of contacts or switches. So, a lotof small contacts or switches can be provided at the sensor surfacewhich are switched by the contact with the elastic sensor body. Wth anincrease of the contact area of the sensor body with the sensor surface,more contacts or switches are closed so that by the termination of thenumber of actuated contacts or switches it is possible to determine thecontact area (and so the sensor force). Here, it is possible that onlythe sensor surface is electrified. In this case, the switches of thesensor surface are actuated by the elastic sensor body. However, it isalso possible that a series or matrix of contacts is provided in thesensor surface. In this case, also the elastic sensor body iselectrified. If the elastic sensor body comes into contact with acontact of the sensor surface, an electrical connection is establishedwhich is then evaluated. By the number of the established electricalcontacts or actuated switches determined in this way which depends onthe size of the contact area, it is possible to determine the sensorforce. Within the frame of the invention, a one-dimensional series or atwo-dimensional matrix (even or curved in space) of contacts or switchescan be used. In the case of the use of a two-dimensional matrix withswitches or contacts, the number of actuated contacts or switchesapproximately correlates with the size of the contact area. Instead,when using a one-dimensional series of contacts or switches, arepresentative extension of the contact area (e.g. the diameter of acircular contact area or one dimension of an elliptic contact area alonga half axis) is analyzed.

In this context it is possible that within the frame of the inventionfor the first time for the design of the force sensor a design accordingto the publication DE 102 28 185 A1 (corresponding to U.S. Pat. No.7,534,973 B2) is used, the publication generally relating to a sensorfor a technological field differing from tools:

The publication DE 102 28 185 A1 discloses an input sensor which ismanually actuated by a finger. The input sensor is removably arranged ona touchscreen or at a housing of a Palm computer or of a smartphone. Aninput sensor of this type might e.g. be used as a kind of small joystickor so-called trackpoint for controlling a mouse curser. The input sensorproposed in DE 102 28 185 A1 comprises an input plate or an input buttonactuated against a spring by the finger. On the lower side, the inputplate comprises a calotte which is pressed against a contact matrixdependent on the input force applied by the finger upon the input plate.Dependent on the input force, the contact area between the calotte andthe contact matrix changes. The calotte comprises an electricallyconducting contact coating on the side facing towards the contactmatrix. Dependent on the input force and the size of the contact area,the number of the contacts established between the contact coating ofthe calotte and the contact matrix changes. Wth the determination of thenumber of the closed contacts then the effective input force can bedetermined. If the input plate is not only moved by a translatorymovement vertical to the contact matrix and not only elasticallysupported in this direction, from a deflection of the contact surfacebetween the contact matrix and the contact coating a pivoting of theinput plate can be determined so that the input sensor can also be usedas a kind of pivot switch. The contact matrix consists of a plurality ofelectric single contacts having a series contact arrangement which canbe applied upon a base plate being designed as a circuit board. If thecalotte itself is manufactured from an electrically conductive material,it is possible not to use a contact coating. By the choice of the sizeand the stiffness of the calotte it is possible to define thesensitivity of the input sensor with respect to the input force appliedby the finger. It is also possible that the contact matrix comprisesconductive paths having a grid-like design. Here, for a large number ofcontact points it is possible that conductive paths extend in differentelectrically separated planes. As an alternative to a contact coating ofthe calotte or to the electrically conductive design of the calotte, itis possible that between the input plate and the conductive paths apolyester-dome sheet is arranged which on the one hand fulfils thefunction of an elastic support of the input plate and on the other handwith a conductive coating of the lower side (e.g. of carbon, metal andthe like) fulfils the function of the contact medium. A resolution ofthe sensed input force can be influenced by the choice of the number ofmatrix elements of the contact matrix. The disclosure of the publicationDE 102 28 185 A1 is incorporated by reference to the disclosure of thepresent patent application.

For another embodiment of the invention, the pressing tool, crimpingtool or cutting tool comprises an electronic control unit for analyzingthe measurement signal of the sensor. Here, it is possible that theelectronic control unit cooperates with other electrical or electroniccomponents, e.g.

-   -   a binary or stepped display or diodes which indicate if a        progression of the sensor force or the sensor displacement or a        maximum of the sensor force or a maximum of the sensor        displacement (within predefined limits) concurs with the ideal        progression or an ideal maximum,    -   a continuous notification or a display for displaying a curve or        a representative value of the working force or sensor force or        the sensor displacement,    -   a storage unit for storing and for the later documentation of        the progression of the working force during a working stroke and        the like.

In a further embodiment of the invention, the electronic control unitcomprises control logic. The control logic determines the forcemeasurement signal from an electric contact area signal correlating tothe size of the contact area under consideration of a calibrationfactor, a calibration curve or a characteristic map or underconsideration of a dependency of the size of the contact area from thesensor force biasing the force sensor, under consideration of a leverarm of the sensor force, under consideration of a spring characteristicof the elastic supporting element and/or under consideration of a leverarm of the supporting force. Here, the calibration factor, thecalibration curve or the characteristic map, the dependency, the leverarms and/or the spring characteristic can be known a-priori and/or canbe stored in a permanent storage unit associated with the electroniccontrol unit. However, it is also possible that (in the factory or bythe user for the first time of use, during a repair or in anypost-calibration interval) the calibration factor, the calibration curveor the characteristic map, the dependency, the lever arms and/or thespring characteristic are “learned” or are input via the electroniccontrol unit.

For another proposal of the invention, the electronic control unitcomprises control logic by which it is possible to calibrate the toolfor working processes. On the basis of the control logic, the followingsteps can be executed:

a) At first, an execution of a calibration working stroke or of aplurality of calibration working strokes is initiated. The tool can e.g.comprise a button or switch being accessible from the outside or awireless or wired device. With the actuation of the device it ispossible to initiate the execution of the calibration working strokes.It is possible that this initializing is performed in the factory of themanufacturer or the initializing is performed by a customer or the userof the tool. Furthermore, the calibration can be initiated in order toexecute a first calibration or a post-calibration of the toolindependent on the intended use. However, it is also possible that anindividual calibration of the tool is performed for a specific intendeduse which is then preferably done by the customer or user of the tool.If e.g. with the tool for a specific intended use a specific type ofplug has to be crimped to a specific type of cable, after the initiationa plurality of calibration working strokes can be executed with aplurality of samples of this type of plug and this type of cable. Afterthe execution of the calibration, then it is possible to crimp this typeof plug with the associated type of cable with this tool. If then for alater point in time the tool has to be used for plugs and/or cables ofdifferent types, a new calibration has to be initiated and executed.

b) If a calibration as explained above has been initiated, a calibrationworking stroke or a plurality of calibration working strokes isexecuted. Here, the measurement signals of the sensor are sensed. If thecalibration working strokes have been executed according to thespecifications, representative measurement signals are available on thebasis of which then for the subsequent use of the tool a monitoring ofthe execution of working strokes according to the specifications can beprovided. For the example mentioned under a) these representativemeasurement signals are the force signals and displacement signals whichoccur when crimping the mentioned type of plug with the associated typeof a cable according to the specifications.

c) From the measurement signals recorded during the calibration workingstrokes then representative data, a calibration factor, a calibrationcurve, a characteristic map and/or representative fluctuations can bedetermined from a plurality of measurement signals. For the examplementioned under a), b), as a representative value e.g. the maximum or amean value of the maxima of the measurement signals can be determinedand used. It is also possible that additional to the maximum of themeasurement signals or a mean value of the respective maxima thefluctuation width of the maximum for the plurality of calibrationworking strokes is determined. It is e.g. possible that when using thetool for crimping specific types of plugs and cables by means ofcalibration working strokes it has been determined that the maximum ofthe measurement signals is in a range of 95% to 105% of a characteristicvalue. In order to mention only some non-limiting example, therepresentative data might also be an increasing slope of the measurementsignal with time or the increasing slope of the measurement signaldependent on the displacement signal which correlates to the movement ofthe hand levers of the tool during the working stroke or correlates tothe movement of a drive element being in driving connection with thehand lever.

d) Under use of the representative data, the calibration factor, thecalibration curve, the characteristic map and/or the representativefluctuations, then an evaluation of the quality of working processeswith the tool after terminating the calibration is performed. If for theaforementioned example after the calibration the tool is used forcrimping and during the working stroke only a maximum of the measurementsignal of 90% or 110% is reached, an indicator is available that thequality of the performed working process is not sufficient.

It is also possible that dependent on the manufacturing tolerances for aplurality of tools having the same design the absolute value of themeasurement signal differs for ideally the same calibration workingstrokes. When using a relative deviation of a maximum during a workingprocess from the maximum of the specific tool during the calibrationworking strokes as explained above, a reliable evaluation of the qualityof the working process independent on the manufacturing tolerances andindependent from the different absolute values of the measurementsignals resulting therefrom can be performed.

The result of the aforementioned analysis can be used in a plurality ofways. In order to mention only one non-limiting example, e.g. a warninglamp or diode might signal to the user that the quality of the performedworking process is unsatisfactory. It is also possible that the resultof the analysis is stored so that it is possible to read the result at alater point in time and/or to use the result for the purpose ofdocumentation.

Another solution of the object underlying the invention is given by atool group. The tool group comprises at least one first pressing tool,crimping tool or cutting tool and at least one second pressing tool,crimping tool or cutting tool. Here, the first and second pressingtools, crimping tools or cutting tools have a design as described above.However, the first and second pressing tools, crimping tools or cuttingtools are pressing tools, crimping tools or cutting tools of differenttypes and/or for different maxima of the working forces. According to anembodiment of the invention, the first pressing tool, crimping tool orcutting tool on the one hand and the second pressing tool, crimping toolor cutting tool on the other hand have the same sensors but differingsupporting elements. In this case, it is possible to achieve a highnumber of the same components due to the use of the same sensors despiteof the different types of the pressing tools, crimping tools or cuttingtools and/or the different maxima of the working forces. This can beprovided by using different supporting elements which in particulardiffer with respect to the effective stiffnesses.

Advantageous developments of the invention result from the claims, thedescription and the drawings. The advantages of features and ofcombinations of a plurality of features mentioned at the beginning ofthe description only serve as examples and may be used alternatively orcumulatively without the necessity of embodiments according to theinvention having to obtain these advantages. Without changing the scopeof protection as defined by the enclosed claims, the following applieswith respect to the disclosure of the original application and thepatent: further features may be taken from the drawings, in particularfrom the illustrated designs and the dimensions of a plurality ofcomponents with respect to one another as well as from their relativearrangement and their operative connection. The combination of featuresof different embodiments of the invention or of features of differentclaims independent of the chosen references of the claims is alsopossible, and it is motivated herewith. This also relates to featureswhich are illustrated in separate drawings, or which are mentioned whendescribing them. These features may also be combined with features ofdifferent claims. Furthermore, it is possible that further embodimentsof the invention do not have the features mentioned in the claims.

The number of the features mentioned in the claims and in thedescription is to be understood to cover this exact number and a greaternumber than the mentioned number without having to explicitly use theadverb “at least”. For example, if an element is mentioned, this is tobe understood such that there is exactly one element or there are twoelements or more elements. Additional features may be added to thesefeatures, or these features may be the only features of the respectiveproduct.

The reference signs contained in the claims are not limiting the extentof the matter protected by the claims. Their sole function is to makethe claims easier to understand.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, the invention is further explained and described withrespect to preferred exemplary embodiments illustrated in the drawings.

FIG. 1 schematically shows a part of a pressing tool, crimping tool orcutting tool comprising a tool jaw which is supported by a force sensorwith an elastic supporting element in parallel arrangement (here with apivoting degree of freedom of the tool jaw and a pivoting measuringdegree of freedom).

FIG. 2 shows a constructive design of a manually actuated pressing tool,crimping tool or cutting tool in a three-dimensional partly disassembledrepresentation.

FIGS. 3, 5, 7 in a side view show a force sensor with different biasingsensor forces.

FIGS. 4, 6, 8 show the resulting different contact areas between asensor surface and an elastic sensor body of the force sensor for thedifferent sensor forces according to FIGS. 3, 5 and 7.

FIG. 9 shows a detail IX of the force sensor according to FIG. 7.

FIG. 10 in a plan view shows a contact area of an elastic sensor bodycontacting a sensor surface of the force sensor which is embodied as amatrix of contacts or switches.

FIG. 11 schematically shows different characteristic curves of forcesensors, e.g. for different assembly conditions and/or tolerances.

FIGS. 12 to 15 show pressing tools, crimping tools or cutting tools withdifferent elastic supporting elements.

FIG. 16 in a three-dimensional view shows a pressing tool, crimping toolor cutting tool wherein a supporting element extends through a recess ofa cover plate of the tool head.

FIG. 17 schematically shows a force sensor with integrated limitingdevice for the sensor stroke of the force sensor.

FIG. 18 schematically shows a limiting device being effective betweenthe tool jaw and the supporting body or tool head in the neighborhood ofa force sensor.

FIG. 19 in a schematic view shows a part of a pressing tool, crimpingtool or cutting tool comprising a tool jaw which is supported by a forcesensor with an elastic supporting element in parallel arrangement (herewith a translatory degree of freedom of the tool jaw and a translatorymeasuring degree of freedom).

DETAILED DESCRIPTION

In the following description reference is made to a sensor with thereference numeral 84. The sensor 84 might be a force sensor 16 or adisplacement sensor 77. Preferably, in the description reference is madeto the embodiment of the sensor 84 as a force sensor 16. However, thecorresponding also applies for the design of the sensor 84 as adisplacement sensor 77.

FIG. 1 very schematically shows a principle sketch of a pressing tool 1,crimping tool 2 or a cutting tool 3 which is in the following for thescope of simplification also denoted as tool 4. The tool 4 comprises atool jaw 5. The tool jaw 5 is supported for being pivoted relative to atool head 7 (in particular a cover plate 8 or a machine frame) by apivot joint 6. For the shown embodiment the pivot joint 6 comprises abearing lug 9 of the tool jaw 5 and a pivot pin 10 which extends throughthe bearing lug 9. Here, in an end region the pivot pin 10 or also bothend regions are held at the tool head 7, in particular in bores of twocover plates 8. It is possible to pivot the tool jaw 5 about a pivotaxis 11 defined by the pivot pin 10 relative to the tool head 7.

On a side facing away from a die accommodation or workpieceaccommodation 12 the tool jaw 5 is supported with a lever arm ordistance 13 from the pivot axis 11 by an elastic supporting element 14.Furthermore, on the side facing away from the die accommodation orworkpiece accommodation 12 the tool jaw 5 is supported with a lever arm15 by a sensor 84, in particular a force sensor 16. If instead of theforce sensor 16 a displacement sensor 77 is used, the displacementsensor 77 has a corresponding distance 15. In this case, preferably thedisplacement sensor 77 does not provide a support additional to thesupport by the supporting element 14. For the shown embodiment the leverarm 15 is larger than the lever arm 13. Preferably, the difference ofthe lever arms 15, 13 is larger than the sum of the half of theextension 17 of the force sensor 16 and the half of the extension 18 ofthe elastic supporting element 14 in the direction of the lever arms 15,16 so that there is an intermediate space 19 between the force sensor 16and the elastic supporting element 14.

A base 20, 21 of the force sensor 16 respectively of the elasticsupporting element 14 interacts with the tool jaw 5 whereas the oppositebases 22, 23 of the force sensor 16 respectively of the elasticsupporting element 14 are supported at a supporting body 24 which issupported at the tool head 7 or directly formed by the same. The forcesensor 16 comprises an own elasticity. The bias of the tool jaw 5 overthe working stroke of the tool 4 with a working force 25 leads to asplitting of the working force 25 corresponding to the lever arms 13, 15into a sensor force biasing the force sensor 16 as well as into asupporting force biasing the elastic supporting element 14. Due to thelimited stiffness of the elastic supporting element 14 and the forcesensor 16, a change of the distance between the tool jaw 5 and thesupporting body 24 results. This is the case due to a relative movementof the tool jaw 5 and the supporting body 24 corresponding to themeasuring degree of freedom 26 which for the shown embodiment is arelative pivoting measuring degree of freedom 27 about the pivot joint6. The relative movement along the pivoting measuring degree of freedom27 is guided by a guidance 28 which for the shown embodiment is thepivot joint 6. The relative movement leads to a deflection 85 of theforce sensor 16 and a deflection 86 of the elastic supporting element14.

An actuation lever 30 is supported for being pivoted by a pivot joint 29at the tool head 7. For the shown embodiment, the pivot joint 29comprises a bearing lug 31 of the actuation lever 30 and the pivot pin10 which extends through the bearing lug 31. By two mounting bolts 32,33 another tool jaw 34 is mounted to the actuation lever 30. The pivotjoints 6, 29 as well as on the one hand the tool jaw 5 and on the otherhand the actuation lever 30 as well as the tool jaw 34 have the samepivot axis 11 defined by the pivot pin 10. Distant from the pivot axis11 the actuation lever 30 comprises a linkage 35 by which it is possibleto apply an actuation force 36 upon the actuation lever 30. Here, it ispossible to generate the actuation force 36

-   -   manually by hand levers and a generally known drive connection        interposed between the linkage 35 and the hand levers or    -   by an electric, hydraulic or pneumatic drive, in some cases also        with an interposed drive mechanism (which also covers a drive        transmission).

The actuation force 36 aims to pivot the two tool jaws 5, 34 towardseach other. If a workpiece is arranged between the tool jaws 5, 34 (inparticular between cutting edges or dies carried by the tool jaws 5,35), the workpiece is cut or severed, pressed or crimped due to theactuation force 36. Due to the working force 25 applied to the tool jaws5, 34, there is a relative movement of the tool jaw 5 relative to thesupporting body 24 along the pivoting measuring degree of freedom 25which coincides with the generation of a sensor force and supportingforce increasing with the further relative movement.

Preferably, during the working stroke the pivoting movement of the tooljaw 5 is smaller than the pivoting movement of the tool jaw 34 by afactor being larger than 5, 10, 20, 50 or even 100. For the embodimentaccording to the prior art wherein the tool jaw 5 does not comprise ameasuring degree of freedom 26, the tool jaw 5 is also denoted as “fixedtool jaw”, whereas the tool jaw 34 is denoted as “movable tool jaw”. Forthe shown embodiment, in a scissors-like fashion the tool jaws 5, 34 arepivoted about the same pivot axis 11. Preferably, FIG. 1 shows aparallel orientation of the pivot jaws 5, 34 of the tool 4 at the end ofthe working stroke without this necessarily being the case. Within theframe of the invention, there are also embodiments wherein the tool jaw34 is pivoted by the drive about a pivot axis which has a distance fromthe pivot axis 11.

Generally, it is possible that the tool jaws 5, 34 directly form thecutting edges or pressing dies or crimping dies. However, for the shownembodiment the tool jaws 5, 34 are coupled to exchangeable pressing diesor crimping dies by

-   -   two transverse supports extending through the pressing die or        crimping die which are accommodated with a close fit in recesses        37 a, 37 b of the tool jaws 5, 34 having the shape of a half        cylinder and a cross section with an open edge and    -   a mounting screw 38 which extends through aligned bores of the        tool jaws 5, 34 and the pressing dies or crimping dies.

(Concerning the coupling, cp. the further details in the disclosure ofpatent DE 198 02 287 C1).

For the shown embodiment the tool jaw 5 is L-shaped or angled. The pivotjoint 6 is arranged in an end region of a leg of the L, whereas thepressing die or crimping die is supported at the other leg of the L. Atthe opposite side of the other leg of the L the support is provided viathe force sensor 16 and the elastic supporting element 14 at thesupporting body 24.

Optionally, it is possible that another sensor 39 is present which forthe shown embodiment is a displacement sensor 40. The displacementsensor 40 senses the displacement of the actuation lever 30 during itspivoting movement in a predetermined distance from the pivot axis 11.From the sensed displacement it is possible to calculate thedisplacement of the tool jaws 34 corresponding to the drivecharacteristic of the drive mechanism. If both a displacement signal ofthe displacement sensor 40 as well as a force signal of the force sensor16 are available, it is possible to determine a force-displacementprogression during a working stroke of the tool 4. Generally, it ispossible that the sensor 39 is embodied as an angular sensor whichsenses the pivoting angle over the working stroke. Furthermore, it ispossible that a sensor 39 being embodied as a displacement sensor 40directly senses the stroke of a component of the drive mechanism, inparticular a linear stroke of a tool jaw.

For a modified embodiment it is also possible that the tool jaw 5 isdirectly supported at the tool head 7, whereas the guidance 28, theelastic supporting element 14 and the force sensor 16 are integratedinto the force flow between the drive mechanism and the tool jaw 34 insuch a way that by the guidance 28 a measuring degree of freedom 26 isdefined. Along the measuring degree of freedom 26 the elastic supportingelement 14 and the force sensor 16 (arranged in mechanical parallelarrangement) can be biased with a sensor force and a supporting forcewhich correlate with the actuation force being effective in the forceflow.

Furthermore, the invention might be used for tools wherein by any drivea “movable” tool jaw can be moved translatory relative to the other“fixed” tool jaw. In order to mention only a non-limiting example,reference is made to crimping pliers of the applicant with the labels CS10, CSV 10, CS 30. In this case, the guidance, the force sensor and theelastic supporting element might

-   -   be arranged and be effective between a tool head or frame and        the initially “fixed tool jaw” which then is movable along the        measuring degree of freedom under the bias of the force sensor        and the supporting element or    -   be integrated into the force flow of the drive mechanism of the        “movable” tool jaw.

FIG. 2 shows a part of a tool 4 embodied as a crimping tool 2 which ishere embodied as manually actuated crimping pliers 41. The tool head 7comprises a cover plate 8 which forms one piece with a hand lever 42 ofthe crimping pliers 41. The tool jaw 5, the tool jaw 34, the actuationlever 30 (being coupled to each other and designed according to FIG. 1)are supported for being pivoted about the pivot axis 11 by the pivot pin10 at the tool head. Plate-like or block-like supporting body parts 24a, 24 b for supporting the elastic supporting element 14 as well as thesensor 84 (in particular the force sensor 16) are fixed at the tool head7, in particular by welding or screwing. The tool jaw 5 loosely contactsthe side of the supporting element 14 as well as of the force sensor 16which faces away from the supporting body parts 24 a, 24 b. The tool jaw5 is biased in opening direction by a pre-tensioned spring 43. For theshown embodiment, the spring 43 is embodied as spiral-shaped pullingspring. However, also other embodiments of the spring 43 are possible.One spring base of the spring 43 is linked with a distance from thepivot axis 11 to the tool jaw 5 whereas the other spring base is linkedto a bolt 44 which is fixed to the tool head 7. Accordingly, also whennot crimping a workpiece between the tool jaws 5, 34 the elasticsupporting element 14 and the force sensor 16 are biased by a supportingforce and a sensor force which depend on the pre-tension of the spring43.

FIG. 2 shows also a possible drive mechanism 45 by which it is possibleto generate an actuation force 36 biasing the linkage 35 of theactuation lever 30. For this purpose, a toggle lever drive 46 is used.The toggle lever drive 46 comprises toggle levers 47, 48. The togglelevers 47, 48 are connected for being pivoted to each other by a togglejoint 49. The end region of the toggle lever 48 facing away from thetoggle joint 49 is linked by a pivot joint 50 (which here comprises apivot pin 51) to the linkage 35 of the actuation lever 30. The endregion of the toggle lever 47 facing away from the toggle joint 49 islinked by a pivot joint 52 (here a pivot pin 53) to the tool head 7. Inthe extended position of the toggle lever drive 46 the toggle levers 47,48 have an orientation approximately vertical to the connecting axisbetween the pivot joint 50 and the pivot joint 6. However, preferablythe toggle lever drive 46 when approaching the closed position of thetool jaws 5, 34 is in a position with a short distance from the extendedposition without the extended position being passed during the workingstroke.

A movable hand lever 54 is formed as one piece with the toggle lever 48.Wth the pivoting movement of the hand levers 42, 54 towards each otherthe toggle lever drive 46 moves towards its extended position whichcoincides with the generation of an actuation force 36 which is directedin closing direction of the tool jaws 5, 34. In per se known fashion,the crimping pliers 41 might comprise a forced locking unit 55 whichsecures a reached closed position of the hand levers 42, 54 as well asof the tool jaws 5, 34 when not completing the working stroke andprovides the option of an opening of the hand levers 42, 54 as well asof the tool jaws 5, 34 only when having completely run through theworking stroke. Furthermore (in particular in the region of theconnection of the toggle lever 47 with the actuation lever 30) anadjusting device 56 might be present by which a (fine) adjustment of theclosed position of the tool jaws 5, 34 is possible.

FIG. 2 shows that essential parts of the crimping pliers 41 have beenmanufactured in a plate construction. Here, FIG. 2 shows a plate whichforms both the tool head 7 with a cover plate 8 as well as a part of thehand lever 42. In FIG. 2 a corresponding cover plate arranged on theother side has been disassembled. The hand lever 54 with the togglelever 48 is here formed with two parallel plates between which twotoggle levers 47 (being formed with two plates directly lying upon eachother) and the actuation lever 30 are accommodated. Also the tool jaw 34is formed with two plates being spaced apart from each other. The platesextend on both sides of the actuation lever 30. Instead, the tool jaw 5is preferably a massive component which (as can be seen in FIG. 2) mightcomprise a slot or recess on the underside wherein a web of a die can behoused.

For the embodiment according to FIG. 2, the crimping pliers 41 arebiased in opening direction by a spring 57. For the shown embodiment, aspring base of the spring 57 is linked to a bolt 48 carried by the toolhead 7 whereas the other spring base of the spring 57 is linked to theactuation lever 30.

A corresponding construction can also be chosen for the design of apressing tool or a cutting tool or also for pressing pliers or cuttingpliers.

FIG. 3 shows a possible embodiment of a force sensor 16 being usablewithin the frame of the invention. The force sensor 16 comprises anelastic sensor body 59 which might e.g. be an elastomeric body. Theelastic sensor body 59 is fixedly connected to the base 22 of the forcesensor 16. In the direction towards the base 20 the elastic sensor body59 has a cambered or convex shape. The elastic sensor body 59 might beembodied as a calotte or have a semi-spherical or partly spherical shapeor might be semi-cylindrical or partly cylindrical (to mention only somenon-limiting examples). The elastic sensor body 59 and the sensorsurface 60 form a contact area 61. The geometry of the contact area 61depends on the shape of the sensor body. The contact area might e.g. becircular, elliptic or rectangular.

FIG. 4 shows the contact area in a plan view. Without a working force 25being applied, the contact area 61 is very small. Preferably, the smallcontact area 61 without applied working force 25 results from the smallelastic deformation of the elastic supporting element 14 and the elasticsensor body 59 due to the bias by the spring 43.

FIGS. 5 to 8 show the changing conditions when running through theworking stroke. Wth an increase of the effective sensor force 62, thecontact area 61 increases according to a dependency which depends on thelever conditions as well as on the stiffnesses of the elastic supportingelement 14 and the force sensor 16 (here in particular the elasticsensor body 59). For the person with skill, it is obvious that dependenton the geometry of the elastic sensor body 59 and any contour of thesensor surface 60 contact areas 61 might result which are not circularas being the case in FIGS. 4, 6 and 8 but have any other geometry, e.g.an elliptic geometry, a rectangular geometry for a partly cylindricalelastic sensor body 59 and the like.

By the force sensor 16 the sensor force 62 is preferably determined bydetermining the size of the contact area 61. This might (as explained inthe beginning) e.g. be done by measuring the transition resistance whichdepends on the size of the contact area 61. Preferably, here atechnology is used which has been described in another technical fieldin the publication DE 102 28 185 A1:

FIG. 9 shows a detail IX of the force sensor according to FIG. 7 in theregion of the contact area 61. It can be seen that the sensor surface 60at least in a direction of extension 63 comprises a series 64 ofswitches or contacts 65 a, 65 b, 65 c, . . . being arranged withconstant or varying distances. The series 64 and the direction ofextension 63 might e.g. have an orientation in the direction of adiameter of the contact area 61 or a semi-axis e.g. of an ellipticalcontact area 61 or a direction of extension 63 of a rectangular contactarea. The number of switches or contacts 65 which establish a contactwith the elastic sensor body 59 depends on the size of the contact area61 and so also on the size of the sensor force 62. If the number of theswitches or contacts 65 being contacted by the elastic sensor body 59 isdetermined in an electronic fashion, from this number it is possible todetermine the sensor force 62 (and so the working force 25). In the casethat switches 65 are used, by a contact of the sensor body 59 with therespective switches 35 the generally open switches 65 are closed so thatcurrent passes the switch which can be analyzed for detecting that thisswitch has been contacted. However, it is also possible that contacts 56are used which are then contacted by the sensor body 59 which is in somecases subjected to a current so that with the contact current flows overthe respective contact 56. The contact current can then be analyzed fordetecting which and what number of contacts 56 have established anelectric contact with the sensor body 59.

FIG. 10 shows a modified embodiment with a plan view of the contact area61 and the sensor surface 60. Here, the sensor surface 60 not onlycomprises a series 64 of switches or contacts 65 but instead a pluralityof series 64 a, 64 b, 64 c, . . . arranged one besides another so thathere the switches or contacts 65 are arranged in a kind of matrix 76. Ifhere the number of contacts or switches 65 which are contacted by theelastic sensor body 59 is analyzed in a corresponding way, this numberdirectly correlates to the area of the contact area 61.

(For the purpose of clarification, it is indicated that for the use ofonly one series of switches or contacts 65 only one single series 64 inthe representation according to FIG. 10 is used which is arranged in theregion of the diameter of the formed contact area 61, whereas the otherseries shown in FIG. 10 are not present.)

FIG. 11 shows a curve 66 of a sensor force 67 determined by the forcesensor 16 over the working stroke 68 of the tool 4. Here, the curve 66 ashown with solid line shows the ideal curve. Here, it is possible toconvert the sensor force 67 under consideration of the characteristic ofthe deformation of the elastic supporting element 14 into the effectiveworking force 55. It is also possible that corresponding to thecharacteristic of the force sensor 16 or the elastic sensor body 59 aswell as the geometry of the elastic sensor body 59 the number ofactuated contacts or switches 65 is converted into the effective sensorforce 67. In each case it is possible to determine the effective workingforce 55 on the basis of the curve 66 over the working stroke 68.

The curves 66 b, 66 c show the sensor force 67 over the working stroke68 for a not-ideal curve or process. So, the curve 66 b e.g. shows acurve or process for which due to manufacturing tolerances (e.g. of theelastic supporting element 14) the force sensor 16 is biased at thebeginning of the working stroke without a parallel bias of the elasticsupporting element 14. Accordingly, up to a working stroke 69 there isno parallel bias of the supporting element 14 and the force sensor 16.As a consequence, the sensor force determined by the force sensor 16 hasa very steep slope. When reaching the working stroke 69, then also theelastic supporting element 14 is biased so that the tool jaw 5 issupported in a parallel fashion both by the force sensor 16 as well asby the supporting element 14. Accordingly, generally the curve 66 b forworking strokes being larger than the working stroke 69 comprises acurvature corresponding to the ideal curve 66 a with a shift whichresults from the steep slope up to the working stroke 69.

Instead, the curve 66 c shows the progression of the sensor force 67 forthe case that (also due to manufacturing tolerances) at the beginning ofthe working stroke only the elastic supporting element 14 is biasedwhereas up to a working stroke 70 there is no bias of the force sensor.With a sufficient deformation of the supporting element 14 when reachingthe working stroke 70 the supporting element 14 and the force sensor 16are cumulatively biased so that then the curve 66 generally correspondsto the curvature according to the ideal curve 66 a, however with theshift which results from the start of the biasing of the force sensor 16only with the arrival at the working stroke 70. For error sourcesdiffering from manufacturing tolerances of the elastic supportingelement 14, corresponding shifts result.

Preferably, according to one embodiment of the invention the tool 4comprises a control unit by which a calibration is performed such thatdespite of the explained inaccuracies (in particular manufacturingtolerances) non-ideal curves 66 b, 66 c of a sensed sensor force 67 areshifted in such a way that these correspond to the ideal curve 66 a orat least approximate the same. For the execution of a calibration ofthis type, there are different options:

It is e.g. possible that a workpiece or a reference specimen which forthe actuation of the tool 4 leads to a predetermined working force 25(and so the predetermined sensor force 67) is inserted into the tool 4.For a tool 4 with the ideal curve 66 a the force sensor 16 with theassociated control unit in fact determines the predetermined sensorforce, whereas for a tool 4 with the curve 66 b a sensor force being toohigh will be determined, and for the tool 4 with the curve 66 c a sensorforce being too small will be determined. Then, a correction can beprovided with the addition of a sensor force correction value or thesubtraction of a corresponding sensor force correction value leading toa shift of the curves 66 b, 66 c towards the ideal curve 66 a.

Whereas according to FIG. 2 the elastic supporting element 14 is acan-shaped or ton-shaped or cylindrical elastomeric body (in particularmade of a PU material), FIG. 12 shows an embodiment wherein the elasticsupporting element 14 is a leaf spring or bending beam 71. An end regionof the leas spring or bending beam 71 is fixed to the tool head 7 or thecover plates of the same (e.g. by two mounting bolts), whereas at thefreely protruding end region a protrusion 72 of the tool jaw 5 issupported.

For the embodiment shown in FIG. 13, the elastic supporting element 14is a spiral-shaped compression spring 73.

However, it is also possible that according to the embodiment shown inFIG. 14 the elastic supporting element 14 is a gas-pressurized spring74.

In order to mention another non-limiting example, according to FIG. 15it is also possible to specifically design the cover plate 8 of the toolhead 7 with an elasticity. In this case, the tool head 7 or the coverplate 8 itself forms the elastic supporting element 14. For theembodiment shown in FIG. 15, the cover plate 8 comprises a recess orcut-out forming a weakening of the cover plate 8 so that the cover plate8 forms a kind of leaf spring or bending beam 71. The free end region ofthe leaf spring or bending beam 71 can be used for supporting a die.

As can be seen from FIG. 16, it is generally possible that the tool head7 (here the cover plates 8) comprise a recess 80 or window into which orthrough which the supporting element 14 and/or the force sensor 16 ordisplacement sensor 77 extend/extends.

By means of a limiting device 81 it is possible to limit the movement ofthe tool jaw 5 along the measuring degree of freedom 26 or to limit thesensor force biasing the force sensor 16.

For the embodiment according to FIG. 17, the limiting device 81 forms anintegral component of the force sensor 16. The limiting device 81defines a maximum sensor stroke 82. The limiting device 81 comprises atleast one stop 83 which blocks a further sensor movement of the forcesensor 16 (and also a further movement of the tool jaw 5) when reachingthe maximum sensor stroke 81.

For the embodiment according to FIG. 18, the limiting device 81 does notform an integral component of the force sensor 16. Instead, here thelimiting device 81 is directly effective between the tool jaw 5 and thesupporting body 24.

A corresponding limiting device 81 might also be used for the design ofthe sensor 84 as a displacement sensor 77 if the displacement sensor 77only has a limited measurement region.

FIG. 19 shows a schematic representation of a tool 4 wherein the tooljaws 5, 34 are guided by a linear guidance 78 for a translatory relativemovement. A tool 4 of this type might e.g. be designed as crimpingpliers of the applicant with the label CS 10 or CS 30. Here, the tooljaw 34 is biased by a drive (in particular hand levers with anassociated drive mechanism) with an actuation force 36 and moved alongthe linear guidance 78 towards the tool jaw 5. On the side facing awayfrom the tool jaw 34, the tool jaw 5 is supported by a sensor 84 (inparticular a force sensor 16) and in mechanical parallel arrangement bya supporting element 14. The linear guidance 78 defines a linearmeasuring degree of freedom 79. Dependent on the working force 25biasing the tool jaw 5, under the bias of both the supporting element 14as well as of the force sensor 16 the tool jaw 5 is moved along themeasuring degree of freedom 79. Also here it is optionally possible thatadditionally a displacement of the tool jaw 34 (or of a drive elementbeing in driving connection therewith) is sensed by a displacementsensor 40 in order to determine a force-displacement-curve with theforce sensor 16 and the displacement sensor 40.

Preferably, the inventive pressing tool, crimping tool or cutting toolis embodied as pressing tool, crimping tool or cutting tool manuallyactuated by two hand levers.

Within the frame of the invention, the sensor 84 and the elasticsupporting element 14 are arranged in mechanical parallel connectionbetween two components 87, 88 which are arranged in the force flow ofthe pressing tool, crimping tool or cutting tool 1, 2, 3. Here, the twocomponents 87, 88 are arranged in mechanical series arrangement. It ispossible that the two components 87, 88 are biased by the working forceof the pressing tool, crimping tool or cutting tool 1, 2, 3. However, itis also possible that the two components 87, 88 are only biased by adefined portion of the working force of the pressing tool, crimping toolor cutting tool 1, 2, 3. The components 87, 88 can be arranged at anyposition in the drive mechanism of the pressing tool, crimping tool orcutting tool 1, 2, 3 between a drive (in particular hand levers) and atool jaw 5 (including the same). In this case, it is also possible thatthe working force biasing the components 87, 88 is geared-up orgeared-down due to the drive mechanism with respect to the forcegenerated by the drive and/or biasing the tool jaw 5. However, it isalso possible (as being the case for the embodiments shown here) thatthe components 87, 88 are integrated into the support of the “fixedpliers jaw 5” (which in this case is not really fixed to the associatedfixed hand lever 42 but is displaced or pivoted relative to the handlever 42 according to the displacement or pivoting movement of thesupporting element 14 and of the sensor 84.

It is possible that the two components 87, 88 are only coupled to eachother by at least one elastic supporting element 14 and the sensor 84.However, preferably the two components 87, 88 are additionally coupledto each other by a guidance 28 which is e.g. a linear guidance or apivot joint.

The components 87, 88 can each be embodied as one-pieces ormulti-pieces. For a multi-piece design the parts can (directly orindirectly) be rigidly connected to each other. Here, it is generallypossible that a component 87, 88 consists of at least two parts. In thiscase, the elastic supporting element 14 is supported at one part and thesensor 84 is supported at another part. In this case, it is evenpossible that the two parts are not (directly or indirectly) rigidlyconnected to each other over the working stroke but the parts are ableto execute a defined relative movement which depends on the workingstroke and which is predetermined by the drive mechanism.

For the embodiments shown here, the components 87, 88 are embodied astool jaw 5 and supporting body 24 without the invention being limited tothis design.

The sensor 84 and the elastic supporting element 14 are deflected withdeflections 85, 86 correlating to each other. In the case of a guidanceof the components 87, 88 relative to each other by a pivot joint 29, thedeflections 85, 86 correlate according to the distances 13, 15 from thepivot axis 11 of the pivot joint 29 (cp. FIG. 1). Instead, in the caseof a guidance of the components 87, 88 relative to each other by alinear guidance 78 the deflections 85, 86 correlate to each other bybeing the same (cp. FIG. 19).

Without this necessarily being the case, the pivot joint 6 providing theguidance 28 might be multifunctional by forming also the pivot joint 29for another component (in particular the other tool jaw 34 or anactuation lever 30). Here, the other component can be pivoted relativeto the tool jaw 5 which supports the supporting element 14.

The embodiment of the sensor 84 shown in FIGS. 3 to 10 is only oneexample of a force sensor 16 being usable within the frame of theinvention. Without a restriction of the invention to the followingfurther embodiments of a sensor 84 being intended, in particular sensors84 basing on the following principle might be used:

-   -   It is possible to use a capacitive displacement sensor. Here it        is possible that a capacitive displacement sensor senses a        relative movement of two circuits boards. In this case, the        circuit boards might comprise one couple or a plurality of        couples of rows of electrodes wherein the rows of electrodes        each comprise a plurality of electrodes being arranged with        constant distances and being commonly electrically biased. The        rows of electrodes are biased by a test signal. A sensed        transfer function between the rows of electrodes which depends        on the relative positions of the circuit boards and the        associated couples of rows of electrodes is analyzed in order to        sense the displacement which correlates to the relative movement        of the circuit boards. A possible embodiment of a capacitive        displacement sensor of this type is e.g. described in the        publication U.S. Pat. No. 4,879,508 A. The disclosure of this        publication is incorporated by reference into the present patent        application with respect to the technical design of a capacitive        displacement sensor.    -   It is possible that a potentiometer or a sheet-potentiometer is        used as displacement sensor. It is e.g. possible that        sheet-potentiometers are used which are described on the website        www.metallux.de and which are distributed under the label        “Foliensensor linear MTP-L”, “Foliensensor linear MTP-LX” or        “Foliensensor Wegerfassung kontaktlos magnetisch MMP”.    -   Furthermore, it is possible that an optical displacement sensor        is used. An optical displacement sensor of this type might e.g.        comprise measurement rods made of glass which might comprise a        BCD-coding. Examples of usable optical displacement sensors are        e.g. described by and distributed via the website www.keyence.de        as “photoelectric sensors” or “fiber-optical sensors”, cp. also        the patent applications and patents of the company Keyence        Corporation, Osaka, Japan which have been classified in the IPC        classification G01D005.    -   Also the use of an inductive displacement sensor is possible.    -   Possible is also the use of a mechanical displacement sensor        wherein e.g. a pointer or needle of the displacement sensor is        moved with the working stroke and which remains at the end of        the working stroke at the reached position so that the maximum        value of the working force is displayed. It is also possible        that when exceeding a threshold value the mechanical        displacement sensor actuates a mechanical counter so that the        mechanical counter is able to display the number of passed        working strokes of a tool.    -   Furthermore, it is possible that a magnetic sensor or a        Hall-sensor is used. These sensors might be used in any design.        It is possible that only a distance of a magnet from a sensor        for detecting the magnetic field is changed so that it is        possible to sense a displacement on the basis of a sensed change        of the magnetic field. For another embodiment it is also        possible that a magnetic strip comprises an alternating        permanent magnetic field over its longitudinal extension. The        magnetic strip is then moved relative to a receiver for the        magnetic field. Options of displacement sensors of this type can        e.g. be taken from the website        www.ams.com/eng/products/magnetic-position-sensors under the        heading “Linear position”. A Hall-sensor of the type AS5510 as        distributed under this heading can e.g. be used.    -   It is also possible that a displacement sensor is used wherein a        shadowing element is moved between a light emitter and a light        receiver (e.g. a photo-transistor and an LED). Dependent on the        deflection of the displacement sensor, the extent of the        shadowing of the light path from the light source to the light        receiver changes. The shadowing element might be a slider, a        shadowing window and the like. It is also possible that e.g. a        foamed material or another partially light translucent material        is arranged between the light emitter and the light receiver,        the foamed material or the partially light translucent material        being compressed more or less dependent on the displacement of        the displacement sensor which leads to the change of the        translucence.    -   It is possible that a laser-based displacement sensor is used.

It is possible that a sensor is used wherein the displacement path isdigitized with at least 100 steps. However, it is also possible that thedigitization comprises more than 200, 300, 500 or even 1,000 steps.

Preferably, the measurement sensor works with an operational voltagewhich is higher than 1 V, 2 V, 3 V. The operational voltage might e.g.be in the range between 3 and 5 V. Typically, sensors used according tothe prior art use a voltage which is (in some cases) one magnitude lowerwhich leads to the disadvantage that for the sensors known from theprior art oscillations of the electric power supply (in particular by abattery of the pressing tool, crimping tool or cutting tool) lead tohigher measurement errors. For one embodiment of the inventive sensor itis possible that the desired signal (so a measurement signal generateddependent on the maximum of the deflection or dependent on a change of ameasurement signal) is more than 10%, more than 20% or even more than30% of the power supply signal.

For the shown embodiments in each case a sensor 84 is used which sensesthe force or the displacement in a linear or almost linear measurementdirection. However, within the frame of the invention also a sensor 84embodied as a rotational sensor can be used which senses a rotationalangle of a component 88 or of the tool jaw 5. It is also possible thatthe sensor 84 senses a sensor moment or torque by which the component 88or the tool jaw 5 is supported. Also in these cases the elasticsupporting element 14 and the sensor 84 are arranged in parallelarrangement. Accordingly, the elastic supporting element 14 and thesensor 84 have deflections correlating to each other and being definedby the geometry. However, the elastic supporting element 14 and thesensor 84 are biased with different forces or moments.

Within the frame of the invention, an inventive pressing tool might alsobe a tool which is used for generating the required pressing forces forjoggling, clinching or toxing a workpiece.

The sensor 84 might have any extension in measuring direction.Preferably, the sensor 84 has an extension in measuring direction ofless than 1.5 cm, 1.2 cm, 1.0 cm, 0.8 cm or 0.5 cm. In this case,despite of the small extension the aforementioned inventive maximumdeflections 85 of the sensor 84 can be provided. It is also possiblethat the maximum deflection 85 of the sensor 84 is more than 5%, morethan 10%, more than 15%, more than 20% or even more than 30% of theextension of the sensor 84 in measuring direction.

Many variations and modifications may be made to the preferredembodiments of the invention without departing substantially from thespirit and principles of the invention. All such modifications andvariations are intended to be included herein within the scope of thepresent invention, as defined by the following claims.

I claim:
 1. A jaw tool comprising: a) a drive mechanism comprising afirst toggle lever and a second toggle lever, and b) a first tool jawand a second tool jaw, at least the first tool jaw being driven by thedrive mechanism over a working stroke from an open position into aclosed position generating a working force, wherein the first tool jawis pivotable relative to the second tool jaw about a pivot joint,wherein the first toggle lever is pivotally coupled to the second togglelever about a toggle joint, and wherein the first toggle lever ispivotably coupled to a tool head of the jaw tool; c) a supporting body,wherein a first one of the tool jaws and the supporting body arearranged in mechanical series arrangement and biased with the workingforce, d) wherein an elastic supporting element and a sensor areinterposed between the supporting body and the first one of the tooljaws in mechanical parallel arrangement such that the sensor and theelastic supporting element are biased with correlating deflections, ande) a stiffness of the elastic supporting element is dimensioned suchthat for a maximum of an effective working force of the jaw tool thesensor is biased with a maximum deflection which is at least 1°.
 2. Thejaw tool of claim 1, wherein the first one of the tool jaws is supportedat the supporting body by a guidance, the guidance providing a measuringdegree of freedom.
 3. The jaw tool of claim 2, wherein the guidance is alinear guidance and the measuring degree of freedom is a translatorymeasuring degree of freedom of the first one of the tool jaws relativeto the supporting body.
 4. The jaw tool of claim 2, wherein the guidanceis a pivot joint and the measuring degree of freedom is a pivotingmeasuring degree of freedom of the first one of the tool jaws relativeto the supporting body.
 5. The jaw tool of claim 1, wherein the sensorloosely contacts at least one of the first one of the tool jaws and theelastic supporting element.
 6. The jaw tool of claim 2, wherein thefirst one of the tool jaws, the sensor or the elastic supporting elementis biased by a spring along the measuring degree of freedom.
 7. The jawtool of claim 1, wherein the elastic supporting element comprises anelastomeric body.
 8. The jaw tool of claim 1, wherein the elasticsupporting element comprises a metallic spring body.
 9. The jaw tool ofclaim 2, wherein a) the jaw tool comprises a tool head which is notmovable over the working stroke, the tool jaws being guided by theguidance relative to the tool head, and b) the elastic supportingelement and the sensor are arranged in a force flow between the toolhead and the first one of the tool jaws.
 10. The jaw tool of claim 9,wherein the tool head comprises at least one cover plate a) whichcarries the guidance and b) at which the elastic supporting element andthe sensor are supported.
 11. The jaw tool claim 10, wherein at leastone cover plate comprises a recess into which or through which theelastic supporting element or the sensor extends.
 12. The jaw tool ofclaim 1, wherein the sensor is a displacement sensor.
 13. The jaw toolof claim 1, wherein the sensor is a force sensor.
 14. The jaw tool ofclaim 12, wherein a limiting device is provided by which a sensordisplacement of the displacement sensor is limited.
 15. The jaw tool ofclaim 13, wherein a limiting device is provided by which a sensor forcebiasing the force sensor is limited.
 16. The jaw tool of claim 13,wherein a) the force sensor comprises an elastic sensor body, b) thesensor body comprises a contact surface contacting a sensor surface ofthe force sensor, c) a size of the contact surface depends on a sensorforce which biases the force sensor and d) the force sensor or anassociated electronic control unit determines the size of the contactsurface and calculates a force measurement signal from the determinedsize of the contact surface.
 17. The jaw tool of claim 16, wherein thesensor surface of the force sensor is formed by a series or matrix ofcontacts or switches.
 18. The jaw tool of claim 16, wherein the size ofthe contact surface is sensed on the basis of a) a surface area of thecontact surface or b) an extension of the contact surface into at leastone representative extension direction.
 19. The jaw tool of claim 17,wherein the size of the contact surface is sensed on the basis of a) asurface area of the contact surface or b) an extension of the contactsurface into at least one representative extension direction.
 20. Thejaw tool of claim 1, wherein the jaw tool comprises an electroniccontrol unit for evaluating a measurement signal of the sensor.
 21. Thejaw tool of claim 16, wherein the jaw tool comprises an electroniccontrol unit for evaluating a measurement signal of the sensor.
 22. Thejaw tool of claim 21, wherein the electronic control unit comprisescontrol logic which determines the force measurement signal from thedetermined size of the contact surface under consideration of a) acalibration factor, a calibration curve or a characteristic map, b) adependency of the size of the contact surface from the sensor forcebiasing the force sensor, c) a lever arm of the sensor force, d) aspring characteristic of the elastic supporting element or e) a leverarm of a supporting force.
 23. The jaw tool of claim 21, wherein theelectronic control unit comprises control logic which provides an optionof a calibration of the jaw tool by executing the following steps: a)initiating an execution of a calibration working stroke or a pluralityof calibration working strokes, b) sensing measurement signals of thesensor during at least one calibration working stroke, c) determinationof representative data, a calibration factor, a calibration curve or acharacteristic map or an offset from at least one measurement signal ofthe sensor or of representative fluctuations from a plurality ofmeasurement signals of the sensor sensed during a plurality ofcalibration working strokes, d) use of the representative data, thecalibration factor, the calibration curve, the characteristic map or ofthe representative fluctuations for an evaluation of the quality ofworking processes with the jaw tool after a termination of thecalibration process.
 24. A jaw tool comprising: a) a drive mechanismcomprising a first toggle lever and a second toggle lever, and b) afirst tool jaw and a second tool jaw, at least the first tool jaw beingdriven by the drive mechanism over a working stroke from an openposition into a closed position generating a working force, wherein thefirst tool jaw is pivotable relative to the second tool jaw about apivot joint, wherein the first toggle lever is pivotally coupled to thesecond toggle lever about a toggle joint, and wherein the first togglelever is pivotably coupled to a tool head of the jaw tool; c) asupporting body, wherein a first one of the tool jaws and the supportingbody are arranged in mechanical series arrangement and biased with theworking force, d) wherein an elastic supporting element and a sensor areinterposed between the supporting body and the first one of the tooljaws in mechanical parallel arrangement such that the sensor and theelastic supporting element are biased with correlating deflections, ande) a stiffness of the elastic supporting element is dimensioned suchthat for a maximum of an effective working force of the jaw tool thesensor is biased with a maximum deflection which is at least 0.1 mm orat least 1°, wherein the first jaw tool and the second jaw tool are ofdifferent types or being designated for different maximum workingforces, and wherein the first jaw tool and the second jaw tool compriseidentical sensors but different elastic supporting elements.
 25. The jawtool of claim 16, wherein the elastic sensor body is an elastomeric bodyformed as at least one of a hemisphere, a calotte, or a half-cylinder.26. The jaw tool of claim 1, wherein the drive mechanism furthercomprises an actuation lever positioned between the first tool jaw andthe second tool jaw, wherein the actuation lever is rotatably coupled tothe first tool jaw and fixedly coupled to the second tool jaw, andwherein the second tool jaw and the actuation lever are pivotable aboutthe pivot joint.